A 90,000-year tephrostratigraphic framework of Aso Volcano, Japan

Miyabuchi, Yasuo

doi:10.1016/j.sedgeo.2009.04.018

Cited by 72 publications

(59 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The average rate of magma discharge at Aso volcano over the past 90,000 years (during the post-caldera stage) is estimated to be ∼1.5× 10 9 m 3 /ky (Miyabuchi 2009). This figure corresponds to a heat discharge rate of 150 MW, assuming a heat capacity of 1,000 J/kg/K, a latent heat of 4×10 5 J/kg (Hardee 1980), a density of 2,600 kg/m 3 , and a temperature decrease of 800°C.…”

Section: Discussionmentioning

confidence: 99%

A water flow model of the active crater lake at Aso volcano, Japan: fluctuations of magmatic gas and groundwater fluxes from the underlying hydrothermal system

2011

View full text Add to dashboard Cite

The first crater of Nakadake, peak of Aso volcano, Japan, contains a hot water lake that shows interesting variations in water level and temperature. These variations were discovered by precise, continuous observations of the lake independent of precipitation. We developed a numerical model of a hot crater lake and compared with observational data for the period from July 2006 to January 2009. The numerical model revealed seasonal changes in mass flux (75-132 kg/s) and enthalpy (1,840-3,030 kJ/kg) for the fluid supplied to the lake. The relation between the enthalpy and mass flux indicates that the bottom input fluid is a mixture of high-and lowtemperature fluids. Assuming a mixture of hightemperature steam at 800°C and liquid water at 100°C, we evaluated the liquid and steam fluxes. The liquid water flux shows a seasonal increase lagging behind the rainy season by 2 months, suggesting that the liquid water is predominantly groundwater. The fluctuation pattern in the flux of the high-temperature steam shows a relation with the amplitude of volcanic tremor, suggesting that heating of the hydrothermal system drives the tremor. Consequently, precise observations of a hot crater lake represent a potential method of monitoring volcanic hydrothermal systems in the shallow parts of the volcanoes.

show abstract

Section: Discussionmentioning

confidence: 99%

A water flow model of the active crater lake at Aso volcano, Japan: fluctuations of magmatic gas and groundwater fluxes from the underlying hydrothermal system

2011

View full text Add to dashboard Cite

show abstract

“…The caldera consists of pyroclastic-flow deposits divided into four units, namely, in ascending order, Aso-1 (270 ka), Aso-2 (140 ka), Aso-3 (120 ka), and Aso-4 (90 ka) [25]. The pyroclastic flows deposited successfully into valleys between the Basement Mountains and formed pyroclastic-flow plateaus after filling these valleys up [5]. Numerous tephra fallout layers were produced after the eruption of four large pyroclastic-flow units.…”

Section: Geological Setting Of the Study Areamentioning

confidence: 99%

“…Usually, for this volcano, the eruption processes involved are strombolian activity, phreatomagmatic explosion, and ash emission [3,4]. Nakadake craters are the most active zones of this volcano, which has a repetitive eruption history [4,5]. There are also three other thermal manifestations of this volcano, namely, the Yunotani, Yoshioka, and Jigoku-Tarutama hot springs, as west zone geothermal features [6].…”

Section: Introductionmentioning

confidence: 99%

“…The Nakadake crater erupted black ash during the first eruption period [4]. One recent study inferred a large-scale hydrothermal system beneath the center cone of the Aso volcano from which fluid and heat flow to the lake of the Nakadake crater [5]. Other recent studies have shown an increase in eruptive activity, including a decrease in the level of lake water, mud eruption, and red hot glows on the crater's wall [7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal Activity Monitoring of an Active Volcano Using Landsat 8/OLI-TIRS Sensor Images: A Case Study at the Aso Volcanic Area in Southwest Japan

2017

View full text Add to dashboard Cite

Thermal remote sensing is currently an emerging technique for monitoring active volcanoes around the world. The study area, the Aso volcano, is currently the most active and has erupted almost every year since 2012. For the first time, Landsat 8 TIRS thermal data were used in this study area to evaluate and monitor the recent thermal status of this volcano, situated in Southwest Japan, from 2013 to 2016 using four sets of images. The total heat discharged rate (HDR), radiative heat flux (RHF), land surface temperature (LST), and land cover (LC) were evaluated, and the relationship between them was determined, to understand the thermal status of the study area. We used the NDVI (normalized difference vegetation index) for land cover, the NDVI-threshold method for emissivity, the split-window algorithm for LST, and the Stefan-Boltzmann equation for radiative heat flux estimation in this study. The total heat discharge rate was computed using a relationship coefficient of RHF and HDR here. The highest HDR was obtained in 2013, at about 4715 MW, and was the lowest in 2016, at about 3819 MW. The total heat loss showed a declining trend, overall, from 2013 to 2016. The highest pixel RHF was in 2013 and the lowest was in 2014; after that, it increased gradually until 2016, coinciding with the LST of this study area. LC showed that, with decreasing heat loss, the vegetated coverage increased and bare land or mixed land decreased, and vice versa. From the spatial distribution of RHF, we saw that, within the Nakadake craters of the Aso volcano, Crater 1 was the most active part of this volcano throughout the study period, and Crater 3 was the most active after 2014. We inferred that the applied methods using the continuous Landsat 8 TIRS data showed an effective and efficient method of monitoring the thermal status of this active volcano.

show abstract

“…ky; Miyabuchi and Watanabe 1997;Miyabuchi 2009), Ojodake volcano (3.6 cal. ky; Miyabuchi and Watanabe 1997;Miyabuchi 2009), Komezuka volcano, Kamikomezuka scoria cone (3.3 cal.…”

Section: Younger Volcanic Vents Along the Faultsmentioning

confidence: 99%

Effects of the 2016 Kumamoto earthquakes on the Aso volcanic edifice

Tajima

Hasenaka

Torii

2017

Earth Planets Space

View full text Add to dashboard Cite

Large earthquakes occurred in the central part of Kumamoto Prefecture on April 14-16, 2016, causing severe damage to the northern segment of the Hinagu faults and the eastern segment of the Futagawa faults. Earthquake surface ruptures appeared along these faults and on the Aso volcanic edifice, which in turn generated landslides. We conducted landform change analysis of the central cones of Aso volcano by using satellite and aerial photographs. First, we categorized the topographical changes as surface scarps, arc-shaped cracks, and linear cracks. Field survey indicated that landslides caused the scarps and arc-shaped cracks, whereas faulting caused the linear cracks. We discovered a surface rupture concentration zone (RCZ) formed three ruptures bands with many surface ruptures and landslides extending from the west foot to the center of the Aso volcanic edifice. The magmatic volcanic vents that formed during the past 10,000 years are located along the north margin of the RCZ. Moreover, the distribution and dip of the core of rupture concentration zone correspond with the Nakadake craters. We conclude that a strong relationship exists between the volcanic vents and fault structures in the central cones of Aso volcano.

show abstract

A 90,000-year tephrostratigraphic framework of Aso Volcano, Japan

Cited by 72 publications

References 15 publications

A water flow model of the active crater lake at Aso volcano, Japan: fluctuations of magmatic gas and groundwater fluxes from the underlying hydrothermal system

A water flow model of the active crater lake at Aso volcano, Japan: fluctuations of magmatic gas and groundwater fluxes from the underlying hydrothermal system

Thermal Activity Monitoring of an Active Volcano Using Landsat 8/OLI-TIRS Sensor Images: A Case Study at the Aso Volcanic Area in Southwest Japan

Effects of the 2016 Kumamoto earthquakes on the Aso volcanic edifice

Contact Info

Product

Resources

About